Mezzanine connector systems typically comprise a plug connector and a receptacle connector that mates with the plug connector. An example is described in U.S. Pat. No. 6,152,747 to McNamara, herein incorporated by reference in its entirety.
The overall height of the mezzanine connector system in the direction of mating is commonly referred to as the stack height of the connector system. A specific stack height is often required for a particular application. If necessary, the stack height can be increased by the use of a spacer. For example, please see U.S. Pat. No. 6,869,292 to Johnescu et al., assigned to the applicant and herein incorporated by reference in its entirety.